C-channel to o-channel converter for a single oeprator exchange biliary catheter

ABSTRACT

A catheter system for use during biliary procedures, including a first elongate member carrying a guidewire lumen, and a channel extending longitudinally along the member which provides access to the guidewire lumen and defines two edge surfaces. A second elongate member is also included which is disposed within the guidewire lumen and mates with the cross-sectional profile of the guidewire lumen of the first elongate member, thereby converting a guidewire lumen having a C-shaped design into one having an O-shaped design. The catheter may be used in rapid exchange catheter procedures requiring the use of small diameter guidewires which would otherwise slip out of the channel during use.

CROSS REFERENCE OF RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 10/767,981, filed Jan. 29, 2004; which is a continuation of U.S.application Ser. No. 09/822,708, filed Mar. 30, 2001, now U.S. Pat. No.6,764,484; the entire disclosures of which are both incorporated hereinby reference.

FIELD OF THE INVENTION

The present invention generally relates to biliary catheters and methodsof use. More specifically, the present invention relates to singleoperator exchange biliary catheters and associated ancillary devices.

DESCRIPTION OF THE PRIOR ART

Endoscopic procedures for treating abnormal pathologies within thealimentary canal system and biliary tree (including the biliary,hepatic, and pancreatic ducts) are increasing in number. The endoscopeprovides access to the general area of a desired duct using directvisualization, however, the duct itself must be navigated using acatheter in conjunction with fluoroscopy and guidewires.

Catheters are known for treatment of targeted anatomical regions. Knownmethods and devices for using biliary catheters for accessing thebiliary tree for performing catheter procedures are disclosed in Weaveret al., U.S. Pat. No. 5,397,302 and Karpiel, U.S. Pat. No. 5,320,602,the disclosures of which are herein incorporated by reference.

In general, for treatment of an abnormal pathology within a patient'sbiliary tree, an endoscope is first introduced into the mouth of thepatient. The endoscope includes a proximal end and a distal end, and hasa lumen extending longitudinally between the proximal and the distalends. The endoscope is guided through the patient's alimentary tract orcanal until an opening at the distal end of the endoscope is proximatethe location for gaining access to the area to receive treatment. Atthis point, the endoscope allows for other components, such as acatheter, to access the targeted area.

For visualization or treatment within the biliary tree, the distal endof the endoscope is positioned proximate the papilla of vater leading tothe common bile duct and the pancreatic duct. A catheter is guidedthrough the lumen of the endoscope until a distal tip of the catheteremerges from the opening at the distal end of the endoscope.

The catheter may be used for accessing the biliary tree. The distal endof the catheter is guided through the orifice to the papilla of vater(located between the sphincter of oddi) leading to the common bile ductand the pancreatic duct. A guidewire may be used for further accessing adesired location within the biliary tree. The guidewire is inserted inan opening at a proximal end of the catheter and guided through thecatheter until it emerges from the distal end of the catheter.

If visualization of the common bile duct is desired, the guidewire isguided into the common bile duct. The catheter is advanced over theguidewire, as previously described, until the distal end of the catheteris positioned in the common bile duct at the desired location. Thecatheter is now in position for delivery of contrast media forfluoroscopic visualization of anatomical detail within the common bileduct. Once the guidewire is placed, it is desirable to maintain positionof the guidewire during subsequent catheter procedures, includingcatheter exchange procedures.

Present biliary endoscopic procedures include the use of multi-lumencatheters for endoscopic retrograde cholangiopancreatography, endoscopicretrograde sphincterotomy, the use of balloon catheters having retrievalballoons, and other therapeutic and diagnostic procedures. As describedin general above, these present biliary endoscopic procedures areperformed using guidewire techniques. The present devices utilized inthese procedures are at least 180 cm long since they pass through theendoscope, which is commonly at least 150 cm long. Therefore, when usinga standard catheter having a guidewire lumen extending the full lengthof the catheter, guidewires used during these procedures must be atleast 400 cm in length to accommodate the exchanging of differentdevices while maintaining access and position within the biliary tree.The exchange of devices over a 400 cm guidewire is both time consumingand cumbersome.

Due to the length of the guidewire, physicians require at least twoassistants in the room to perform the biliary endoscopic procedure.Typically, one assistant is responsible for the patient anddevice-related concerns, while the other assistant is responsible forthe guidewire. The additional hands required due to the length of theguidewire results in a relatively more time consuming and costlyprocedure.

The present invention provides rapid exchange biliary catheters whichmay include a guidewire lumen having a C-shaped channel through whichthe guidewire is disposed. This design may not allow for the use of verysmall guidewires, such as a 0.018-inch diameter guidewire, if the wirediameter is smaller than the channel. Thus, the physician may face alimited choice of guidewire sizes for use in a biliary procedure whensome types of rapid exchange catheters are being utilized.

It is desirable to have an exchange catheter suitable for use within thealimentary canal for accessing targeted anatomical regions, such as thebiliary tree, having features which facilitate rapid exchange and allowan exchange procedure to be performed by a single operator. It isdesirable to have a biliary exchange catheter which may be used inconnection with a shorter guidewire, and requires less personnel forperforming biliary procedures. It is desirable to have a biliaryexchange catheter which limits the amount of guidewire over which thecatheter must travel.

It is also desirable to have a biliary rapid exchange catheter which maybe convertible for use between conventional guidewire techniques andrapid exchange guidewire techniques. It is desirable to have a biliaryrapid exchange catheter which is easily removable from the guidewire,and adaptable for use with most catheter systems used within thealimentary canal.

It would also be desirable to have a rapid exchange catheter which wouldallow for the use of small diameter guidewires, such as a 0.018-inchguidewire, without the risk of the guidewire slipping out of theguidewire lumen through the channel.

SUMMARY OF THE INVENTION

The present invention relates to a biliary catheter for use in biliaryendoscopic procedures which incorporates rapid exchange catheterfeatures. Rapid exchange features include an effective guidewire lumenwhich is much shorter than the overall catheter length to facilitaterapid exchange of the device over the guidewire.

In one preferred embodiment, the present invention is an improvedcatheter for use in biliary procedures which includes a shaft having aproximal end and a distal end. The improvement includes a guidewirelumen carried by the shaft extending from a location proximal of thedistal end of the shaft to a location proximate the distal end of theshaft. Means are provided for accessing the guidewire lumen from alocation exterior to the catheter shaft, located a substantial distancedistal of the proximal end of the shaft.

The guidewire lumen may be formed integral with the shaft. The means foraccessing the guidewire lumen may include an opening extending throughthe wall of the catheter shaft. Additionally, the wall of the cathetershaft defined by the guidewire lumen may include a relatively weak areaextending longitudinally between the opening and the distal end of theshaft. The weak area may be perforated. The catheter may further includea tool for guiding a guidewire through the opening into the guidewirelumen.

In a further preferred embodiment, the means for accessing the lumen mayinclude a slit in the wall of the catheter shaft. An ancillary lumen mayextend between the catheter proximal end and the catheter distal end.

In one embodiment, the means for accessing the guidewire lumen includesa first opening or intermediate guidewire port through the wall of thecatheter shaft into the guidewire lumen located proximal of the distalend of the shaft. A second opening or proximal guidewire port into theguidewire lumen is located proximal of the first opening. A channelextends between the first opening and the second opening. The channelincludes a longitudinal opening to the exterior of the catheter shaftextending between the first opening and the second opening incommunication with the guidewire lumen. The longitudinal openingpreferably is smaller than the diameter of a guidewire used therewith.

In another embodiment, the present invention is a biliary rapid exchangecatheter. The biliary rapid exchange catheter includes a biliarycatheter sized for passage within an endoscope including a shaft havinga proximal end and a distal end. The biliary catheter includes a tubularmember having a proximal end, a distal end, and a guidewire lumenextending longitudinally therethrough which extends between a locationproximate the distal end of the shaft (a distal port) to a locationproximal of the distal end of the shaft (a proximal port). The proximalport is provided in communication with the guidewire lumen, at alocation proximal of the distal end of the shaft.

The proximal port may be located at the proximal end of the tubularmember. The guidewire lumen may then extend between the proximal end andthe distal end of the shaft. The guidewire lumen would then include aweakened area extending longitudinally between the proximal port and thedistal end of the shaft. The biliary catheter may further include anancillary lumen extending between the proximal end and the distal end ofthe shaft.

The biliary catheter may alternatively include an intermediate port intothe guidewire lumen at a longitudinal location between the proximal portand the distal end of the shaft or distal port. Means are includedextending longitudinally between the proximal port and the intermediateport for allowing a guidewire to be moved between a location exterior ofthe guidewire lumen to a location within the guidewire lumen between theproximal and intermediate ports. The means for allowing the guidewire tobe moved between a location exterior the guidewire lumen and within theguidewire lumen include an open channel extending longitudinally betweenthe proximal port and the intermediate port.

The means for allowing the guidewire to be moved between a locationexterior the guidewire lumen and within the guidewire lumen may includea weakened portion within the tubular member extending longitudinallybetween the proximal port and the intermediate port. The weakenedportion may be perforated.

The biliary rapid exchange catheter may also include a second tubularmember having a cross-sectional profile which serves to convert thechannel of the catheter from a C-shaped design to an O-shaped design.The tubular member is inserted through the channel and into theguidewire lumen, and is extended longitudinally therein. The tubularmember includes a lumen for receiving a guidewire.

In another embodiment, the present invention includes a method ofpositioning a biliary catheter including a shaft having a proximal endand a distal end, within a patient's alimentary canal. The methodincludes the step of providing a catheter with a guidewire lumentherein. The guidewire lumen extends from a location proximal of thedistal end of the shaft to a location proximate the distal end of theshaft. A port is provided through a sidewall of the shaft into theguidewire lumen. The port is located distal of the proximal end of theshaft. The method further includes the step of moving a guidewirethrough the port, relative to the shaft. The method may further includethe step of advancing the catheter over the guidewire.

In another embodiment, the present invention includes a method ofexchanging a catheter during a biliary endoscopic procedure. The methodincludes the step of passing an endoscope having a lumen extendinglongitudinally therethrough, through a patient's mouth into thealimentary canal. A distal end of the endoscope is positioned proximatean opening into the biliary tree. A guidewire is passed through thelumen of the endoscope.

A catheter is provided having a guidewire lumen carried by the shaft,extending from a location proximal of a distal end of the shaft to alocation proximate the distal end of the shaft. A first opening isincluded into the guidewire lumen, located distal of the proximal end ofthe shaft. The catheter is advanced over the guidewire, wherein aproximal end of the guidewire exits the first opening.

The method may further include retracting the catheter over theguidewire. In one embodiment, wherein the catheter is retracted over theguidewire until the opening is outside the proximal end of theendoscope, the catheter has a weakened area extending longitudinallybetween the opening and the distal end of the catheter. The methodfurther comprises the step of peeling the catheter away from theguidewire.

The catheter may further include a second opening or intermediateopening into the guidewire lumen. A channel extends longitudinallybetween the first opening and the second opening. The method furthercomprises the step of passing the guidewire radially through the channelopening while inserting or retracting the catheter until the guidewireexits the second opening.

In one embodiment, the present invention additionally includes a methodof exchanging guidewires during a biliary endoscopic procedure. Themethod includes the step of inserting a second tubular member having alumen through the channel into the guidewire lumen and advancing itlongitudinally therein before advancing the catheter over the guidewire

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described with reference to theaccompanying drawings, wherein like numbers refer to like parts inseveral views and wherein:

FIG. 1 is a partial elevational view of a catheter in accordance withthe present invention having a guidewire lumen for facilitating rapidcatheter exchange with a guidewire passing therethrough;

FIG. 1A is a cross-sectional view of the catheter of FIG. 1 taken alongline 1A-1A;

FIG. 1B is a cross-sectional view of the catheter of FIG. 1 taken alongline 1B-1B;

FIG. 1C is a cross-sectional view of the catheter of FIG. 1 taken alongline 1C-1C;

FIG. 1D is a cross-sectional view of an alternative embodiment of thecatheter of FIG. 1 in accordance with the present invention, also takenalong line 1C-1C;

FIG. 1E is a partial elevational view of an alternative embodiment ofthe catheter in accordance with the present invention;

FIG. 1F is a cross-sectional view of the catheter of FIG. 1E taken alongline 1F-1F;

FIG. 2 is a partial elevational view of another embodiment of thecatheter in accordance with the present invention;

FIG. 3 is a partial elevational view of another embodiment of thecatheter in accordance with the present invention;

FIG. 3A is a cross-sectional view of the catheter of FIG. 3 taken alongline 3A-3A;

FIG. 3B is a cross-sectional view of the catheter of FIG. 3 taken alongline 3B-3B;

FIG. 4 is a partial elevational view of another embodiment of thecatheter in accordance with the present invention;

FIG. 4A is a cross-sectional view of the catheter of FIG. 4 taken alongline 4A-4A;

FIG. 4B is a cross-sectional view of the catheter of FIG. 4 taken alongline 4B-4B;

FIG. 5 is a partial elevational view of another embodiment of thecatheter in accordance with the present invention;

FIG. 5A is a cross-sectional view of the catheter of FIG. 5 taken alongline 5A-5A;

FIG. 6 is a different partial elevational view of the catheter of FIG. 5having a guidewire disposed therein;

FIG. 6A is a cross-sectional view of the catheter of FIG. 6 taken alongline 6A-6A showing the guidewire received within the lumen of FIG. 5;

FIG. 7 is a partial elevational view of a catheter assembly showing aguidewire loading tool for use in conjunction with the catheter of FIGS.5 and 6;

FIG. 7A is an alternative partial elevational view of the catheterassembly of FIG. 7 showing an application of the present invention;

FIG. 7B is a partial cross-sectional view of the catheter of FIG. 7taken along line 7B-7B, showing a first guidewire tool position;

FIG. 7C is a partial elevational view of a catheter assembly showing anapplication of the present invention;

FIG. 7D is a partial cross-sectional view of the catheter of FIG. 7taken along line 7B-7B showing a second guidewire tool position;

FIG. 7E is a partial elevational view of a catheter assembly showing anapplication of the present invention;

FIG. 7F is a partial cross-sectional view of the catheter of FIG. 7taken along line 7B-7B, showing a third guidewire tool position;

FIG. 7G is a partial elevational view of a catheter assembly showing anapplication of the present invention;

FIG. 7H is a partial cross-sectional view of the catheter of FIG. 7taken along line 7B-7B, showing a fourth guidewire tool position; and

FIG. 8 is a partial elevational view of a catheter showing anotherapplication of the present invention;

FIG. 9 is a partial elevational view of a catheter showing anotherapplication of the present invention;

FIG. 10A is a partial elevational view of a tubular member which may bedisposed within the catheter's guidewire lumen;

FIG. 10B is a cross-sectional view of the tubular member of FIG. 10Ataken along line 10B-10B;

FIG. 11 is a partial elevational view of a catheter showing the tubularmember disposed within the guidewire lumen;

FIG. 12A is a partial elevational view of an alternative embodiment ofthe tubular member which may be disposed within the catheter's guidewirelumen;

FIG. 12B is a cross-sectional view of the tubular member of FIG. 12Ataken along line 12B-12B;

FIG. 12C is a cross-sectional view of the catheter of FIG. 11 takenalong line 12C-12C;

FIG. 13 is a cross-sectional view of the catheter of FIG. 11, takenalong line 13-13 when the tubular member of FIG. 10A is disposed withinthe guidewire lumen;

FIG. 14 is a cross-sectional view of the catheter of FIG. 11 taken alongline 13-13 when the tubular member of FIG. 12A has been advanced intothe guidewire lumen;

FIG. 15 is a is a cross-sectional view of the catheter of FIG. 11 takenalong line 13-13 in which a guidewire has been inserted into the lumenof the tubular member;

FIG. 16 is a partial elevational view of another embodiment of thecatheter in accordance with the present invention;

FIG. 17A is a cross-sectional view of the catheter of FIG. 16 takenalong line 17-17, showing a channel having a U-shaped cross-sectionalprofile; and

FIG. 17B is a cross-sectional view of the catheter of FIG. 16 takenalong line 17-17, showing a channel having a C-shaped cross sectionalprofile.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention.

FIG. 1 shows a partial elevational view of a catheter assembly 30 inaccordance with the present invention. The catheter assembly 30 is usedin catheter procedures for accessing targeted anatomical regions throughthe alimentary canal. The present invention incorporates features whichallow rapid exchange of catheter by a single operator. The catheter ofthe present invention allows shorter length guidewires to be used,resulting in procedures which require less medical personnel, are lesstime consuming, and less costly. Additionally, the present invention isadaptable to most catheter devices used for catheter procedures withinthe alimentary canal.

Catheter assembly 30 includes a catheter 32 having a guidewire 34passing through a portion thereof. Catheter 32 includes a shaft 36having a proximal end 38 and a distal end 40. Operably connected to theproximal end 38 of the shaft 36 is a hub assembly 42. Hub assembly 42couples to ancillary devices allowing access to a lumen within shaft 36.Shaft 36 is preferably formed in an extrusion process. Shaft 36 may beformed of an extruded polymeric material. In one embodiment, thepreferred polymeric material is polytetrafluoroethylene, polyether blockamide, nylon or a combination or blend of these. Catheters which arecontemplated include, but are not limited to, cannulas, sphinctertomes,cytology devices, and devices for stone retrieval and stent placement.

Shaft 36 is a generally tubular shaped member having a generally uniformouter shape at its proximal end. Shaft 36 may be sized for slidablepassage through the lumen of an endoscope. Shaft 36 includes a distaltaper 44 which tapers to a tip region 46. Tip region 46 may include highcontrast, color-coded distal markers 48, and a radiopaque distal tip 50for fluoroscopic visualization of tip region 46 during a catheterprocedure.

Shaft 36 further includes a proximal port or opening 52 located proximalof distal end 40. Proximal opening 52 allows access to shaft 36 forpassage of guidewire 34 through shaft 36. FIG. 1A is a cross-sectionalview of shaft 36 taken along line 1A-1A at a location proximal ofproximal opening 52. Proximal to proximal opening 52, guidewire 34 ispositioned adjacent the catheter shaft 36.

Extending longitudinally between the shaft proximal end 38 and distalend 40 is an ancillary lumen 54 and an ancillary lumen 56. Ancillarylumen 54 and ancillary lumen 56 may be injection lumens, allowing forhigh contrast media flow capability for bubble-free opacification andfor excellent visualization of a desired anatomical region. Additionallyor alternatively, ancillary lumen 54 and/or ancillary lumen 56 may beused for other ancillary devices, such as a cutting wire lumen or aretrieval balloon lumen.

Referring to FIG. 1B, a cross-sectional view of shaft 36 taken alongline 1B-1B of FIG. 1 is shown. A guidewire lumen 58 extends betweenproximal opening 52 and distal end 40. Guidewire 34 may enter guidewirelumen 58 at proximal opening 52. Guidewire lumen 58 is sized forslidable receipt and passage of guidewire 34 through guidewire lumen 58.Referring to FIG. 1C, guidewire lumen 58 extends through distal taper 44and tip region 46.

Although it is recognized that proximal opening 52 may be located at anylocation distal of proximal end 38, proximal opening 52 is preferablylocated between 10 and 40 cm from distal end 40. Guidewire lumen 58 is atubular member which is carried adjacent shaft 36 ancillary lumen 54 andancillary lumen 56. Guidewire lumen 58 maybe formed integral with shaft36, or alternatively, guidewire lumen 58 may be part of a separatetubular member which is coupled to the shaft 36 as shown in FIG. 1D.

Now referring to FIGS. 1E and 1F, an alternative embodiment of thecatheter depicted in FIG. 1 is illustrated. The catheter shaft 36 ofFIG. 1E incorporates a proximal guidewire opening which, in conjunctionwith the catheter, forms a circular cross section which allows for easyinsertion of the guidewire. As depicted in FIG. 1F, the guidewire lumen58 can include a larger proximal opening which funnels down to the sizeof the guidewire lumen 58 which extends distal to the distal end of thecatheter shaft 36.

Guidewire lumen 58 allows rapid exchange of catheter 32 when analternative catheter is necessary during a procedure. Shorter lengthguidewires may be used since guidewire 34 does not pass through proximalend 38 and hub assembly 42, but rather exits the catheter shaft 36 atproximal opening 52 located substantially distal from proximal end 38.The unique catheter construction in accordance with the presentinvention will reduce catheter therapeutic and diagnostic procedure timesince catheter device exchanges may be performed relatively more easilyand quickly by a single operator. Additional personnel and timeassociated with maintaining the placement of a conventional(approximately 400 cm) guidewire within the targeted anatomical regionis eliminated, reducing the overall costs of the procedure.

Referring to FIG. 2, a partial elevational view of a distal portion ofcatheter shaft 36 is shown. Shaft 36 may further include a weakened area60. The weakened area 60 extends longitudinally along guidewire lumen 58(not shown) between proximal opening 52 and distal end 40.

When guidewire 34 is positioned within guidewire lumen 58, weakened area60 allows guidewire 34 to be removed from guidewire lumen 58 by “peelingaway” guidewire 34 from catheter shaft 36. Weakened area 60 may includeless catheter material than the remaining portion of shaft 36, or may beperforated, cut or slit.

Another embodiment of the present invention is shown generally in FIG.3. FIG. 3 is a partial elevational view of catheter 32, which may be a“convertible” catheter design. In catheter 32, shaft 36 includes anopening 52 which is a skive port 62 for access to guidewire lumen 58.Catheter 32 is a convertible catheter design in that an existingcatheter may be modified to include skive port 62. As a convertiblecatheter design, skive port 62 is formed by cutting an opening in shaft36 for access to guidewire lumen 58. It is recognized that catheter 32may be manufactured to include skive port 62.

Referring to FIG. 3A, proximal to skive port 62 catheter shaft 36includes ancillary lumen 54 and ancillary lumen 56 as previouslydescribed herein. Additionally, shaft 36 includes guidewire lumen 58extending between proximal end 38 and distal end 40, including betweenskive port 62 and proximal end 38. Referring to FIG. 3B, guidewire 34may access guidewire lumen 58 at skive port 62 and extend through theguidewire lumen 58 emerging from distal end 40.

With this embodiment, conventional guidewire techniques may be used forpositioning and exchanging catheter 32 within a patient's alimentarycanal system. Further, the convertible catheter design incorporatesfeatures which allow rapid exchange of catheters by a single operator.Skive port 62 opening 52 allows catheter 32 to be used in rapid exchangeof catheter 32 when an alternative catheter is necessary during aprocedure. By allowing the guidewire 34 to enter the guidewire lumen 58at a location distal from the proximal end 38, relatively shorterguidewires may be used during catheter procedures within the alimentarycanal system, resulting in a more efficient and less costly procedure.

It is recognized that other means for accessing the guidewire lumen 58at a location distal from the proximal end 38 are contemplated withinthe scope of the present invention. Referring to FIG. 4, a weakenedlocation or slit 64 is shown within area A for accessing the guidewirelumen 58. Referring to FIG. 4A, proximal to the slit 64, the guidewiremay be positioned adjacent the catheter shaft 36. Guidewire 34 entersguidewire lumen 58 at slit 64 for passage of guidewire 34 through theguidewire lumen 58. Referring to FIG. 4B, guidewire 34 is slidablycontained within the guidewire lumen 58 at a location distal of the slit64. With this embodiment, since guidewire lumen 58 may extendlongitudinally from the proximal end 38 to the distal end 40,conventional guidewire techniques may also be used during the catheterprocedure.

Referring to FIG. 5, another embodiment of the catheter of the presentinvention incorporating features which allow rapid exchange of cathetersby a single operator is generally shown. The catheter assembly 30includes a “port and channel” configuration. For access to guidewirelumen 34, shaft 36 includes a first opening or intermediate port 66located proximal of the distal end 40. A second opening or proximal port68 is located proximal of the intermediate port 66 and proximal ofdistal end 40. Extending between the intermediate port 66 and proximalport 68 is a longitudinal channel 70.

Guidewire lumen 34 extends longitudinally between proximal end 38 anddistal end 40. Referring to FIG. 5A, channel 70 is located within thewall of catheter shaft 36, providing access to guidewire lumen 58between proximal port 68 and intermediate port 66. Preferably, channel70 includes a radial opening extending between proximal port 68 andintermediate port 66. It is also recognized that channel 70 may be aweakened area within the wall of the catheter shaft, a perforated area,or a slit which extends between proximal port 68 and intermediate port66.

In one embodiment, intermediate port 66 is located near distal end 40,and proximal port 68 is located near proximal end 38. Referring to FIG.6, the distal end of guidewire 34 may be inserted within theintermediate port 66 (not shown), passing through guidewire lumen 58 andemerging from the catheter 32 distal end 40. Referring also to FIG. 6A,guidewire 34 may then be snapped through channel 70 into guidewire lumen58 with the proximal end of the guidewire 34 exiting the proximal port68. With this “port and channel” design, both conventional and rapidexchange techniques may be used.

FIG. 7 shows a partial elevational view of the catheter assembly 30 inaccordance with the present invention including one preferred embodimentof a tool 59. Tool 59 aids in guiding guidewire 34 during a catheterprocedure. Tool 59, shown positioned over catheter shaft 36, includes abody member 80 having a generally tubular shape. The body member 80includes a proximal end 82, a distal end 84, and a lumen 86 extendinglongitudinally therethrough. The lumen 86 is sized for slidable receiptof catheter shaft 36. Located near the proximal end 82 of tool 59 is agripping mechanism 88. Gripping mechanism 88 aids a user in grippingtool 59 during use of tool 59. Located proximal to the distal end 84 oftool 59 is guidewire opening 90. Guidewire opening 90 is brought incommunication with a desired port or opening along the catheter 36 shaftto aid in guiding a guidewire (such as guidewire 34) into guidewirelumen 58.

Referring to FIG. 7A, tool 59 further includes a locking mechanism 92.Referring to FIG. 7B, which is a cross-sectional view of the tool 59shown in FIG. 7A, locking mechanism 92 further includes a locking head94, a stem 96 and an operating mechanism 100.

Operating mechanism 100 is located exterior of body member 80. Operatingmechanism 100 is coupled to stem 96. Stem 96 extends through an opening102 in body member 80, and is coupled to locking head 94. Lockingmechanism 92 is moveable within an interior chamber 104 of body member80.

More specifically, by applying pressure externally to operatingmechanism 100, locking head 94 is moveable within interior chamber 104for moving tool 59 between a locked and unlocked position relative tocatheter shaft 36. When positioned in a locked position (as shown inFIG. 7B), tool 59 is locked onto catheter shaft 36. When in an unlockedposition, tool 59 allows catheter shaft 36 to pass through lumen 86 andmove freely relative to tool 59.

Referring again to FIG. 7A and FIG. 7B, tool 59 is shown in a lockedposition. In this position, locking head 94 friction locks the cathetershaft 36 within lumen 86. As indicated by directional arrow 106, tool 59allows the catheter shaft 36 to be held stationary, while guidewire 34is inserted into the guidewire lumen 58 through an opening or port inthe catheter shaft 36 (such as proximal port 66 or intermediate port 68in FIG. 7).

Referring to FIG. 7C, once guidewire 34 is in place during abiliaryprocedure, it may be necessary to remove the catheter shaft 36.By applying pressure to operating mechanism 100, locking mechanism 92may be moved to an unlocked position, as shown in FIG. 7D. The guidewire34 may be held stationary, and the catheter shaft 36 may be removed(indicated by directional arrow 108), allowing the catheter shaft 36 tobe removed or “peeled away” from the guidewire 34 while the guidewire 34remains positioned within the patient's body.

Referring to FIG. 7E, tool 59 may be used to back load catheter shaft 36onto guidewire 34 positioned within the patient's biliary tree.Referring to FIG. 7F, to start back loading catheter shaft 36 ontoguidewire 34, tool 59 is positioned over the desired opening (such asintermediate opening 68 in the embodiment shown in FIG. 7) and locked tocatheter shaft 36 in a deflected position.

By applying pressure to operating mechanism 100 (indicated bydirectional arrow 110), locking head 94 locks catheter shaft 36 in a“deflected” position. By locking the tool 59 to catheter shaft 36 in adeflected position, tool 59 aids in back loading the catheter shaft 36onto guidewire 34.

To start back loading, the distal end 40 of catheter shaft 36 isinserted over the proximal end of guidewire 34. As catheter shaft 36passes over the guidewire 34, the proximal end of guidewire 34 is guidedthrough the catheter intermediate opening 66, through guidewire opening90, exiting tool 59.

Referring to FIG. 7G, once the proximal end of guidewire 34 is guidedthrough the intermediate opening 66, catheter shaft 36 may continue tobe back loaded onto guidewire 34. Referring to FIG. 7H, by returninglocking mechanism 92 to an unlocked position, guidewire 34 may be heldstationary relative to tool 59, and catheter shaft 36 moves freelywithin lumen 86 (indicated by directional arrow 112), allowing cathetershaft 36 to be loaded onto guidewire 34. As catheter shaft 36 is loadedonto guidewire 34, the tool 59 aids in guiding guidewire 34 throughchannel 70 into the guidewire lumen 58 until guidewire 34 exits proximalopening 68.

Tool 59 aids in guiding guidewire 34 through opening 52 (shown inFIG. 1) or “port and channel” proximal port 68, channel 70, andintermediate port 66 (as shown in FIG. 7). Tool 59 allows for gradualintroduction of guidewire 34 into the guidewire lumen 58 during anendoscopic procedure. As previously described herein, it is recognizedthat tool 59 may be used to hold catheter shaft 36 stationary whileguidewire 34 is being advanced or retracted during a catheter procedure.Alternatively, it is recognized that tool 59 may be used to holdguidewire 34 in place during a rapid exchange procedure or duringadvancement or retraction of catheter shaft 36 over guidewire 34.

It is also recognized that a locking device (not shown) may be locatedproximate first port 66 or proximate second port 68 to aid in guidingguidewire 34 into guidewire lumen 58 during an endoscopic procedure. Thelocking device can be similar to the tool 59 as previously describedherein. Additionally, it is recognized that tool 59 may be used to holdthe catheter shaft 36 in place while guidewire 34 is being advanced orretracted during a catheter procedure. Alternatively, it is recognizedthat tool 59 may be used to hold guidewire 34 in place during a rapidexchange procedure, or during advancement or retraction of cathetershaft 36 over guidewire 34.

It is recognized that the rapid exchange technology of the presentinvention may be utilized in different types of catheter assemblies usedwithin the alimentary canal. Referring to FIG. 8, catheter assembly 30is used as a rapid exchange retrieval balloon system used for stoneretrieval or isolated visualization techniques. Ancillary lumens 54 and56 (FIG. 1A) are available for passage of retrieval balloon catheter 72having a balloon 74 located at its distal end, and for passage of dyeinjection apparatus 76. With this embodiment, the guidewire lumen may beaccessed using conventional guidewire techniques through the proximalend of catheter 32 or using rapid exchange techniques.

Referring to FIG. 9, the rapid exchange designs of the present inventionmay be used for other alimentary canal catheter applications, such as arapid exchange sphincter catheter used for endoscopic retrogradesphincterotomy, shown using a cutting wire apparatus 78. Again, theguidewire lumen (not shown) may be accessed by conventional guidewiretechniques at the proximal end, or alternatively, using the rapidexchange technology of the present invention.

The rapid exchange catheter of the present invention is a multi-lumencatheter. With this invention, the guidewire lumen is isolated from theancillary lumens allowing for exceptional contrast flow for high qualityopacification without the need for guidewire removal. Treatment andtherapeutic devices, such as retrieval balloon catheters or cathetershaving cutting apparatus may be advanced through the ancillary lumens,without interference of a guidewire located within the guidewire lumen.Additionally, isolation of the guidewire lumen from the contrast lumenminimizes the risk of bubble formation during contrast flow and producesa contrast-free guidewire surface for efficient device exchanges.

The rapid exchange biliary catheter of the present invention results inless time consuming and less costly catheter procedures, since a muchshorter guidewire may be used and additional personnel are not requiredto maintain the guidewire position during a catheter procedure. In usein a typical endoscopic procedure, an endoscope is first introduced intothe mouth of a patient and is guided through the patient's alimentarycanal. Specifically, the endoscope is guided down the esophagus, throughthe stomach, past the pyloric sphincter of the stomach and into theduodenum. The endoscope has a lumen extending longitudinally between itsproximal end and the distal end.

The endoscope is guided through the alimentary canal until the distalend of the endoscope is proximate the target area within the anatomy toreceive treatment. In an endoscopic biliary procedure, the endoscope isguided into the duodenum until the opening at the distal end of theendoscope is proximate the papilla of vater. The papilla of vater islocated between the sphincter of oddi, which leads to the common bileduct, hepatic, and pancreatic ducts. The proximate end of the endoscopeextends and remains outside the mouth of the patient.

With general reference to the various embodiments shown in FIGS. 1-7,once the endoscope is in proper position, guidewire 34 is inserted intothe proximal opening of the endoscope and advanced through the lumen ofthe endoscope until guidewire 34 distal end emerges from the opening atthe distal end of the endoscope. The distal tip of guidewire 34 may beguided through the orifice leading to the papilla of vater for accessinto the biliary tree.

Once the distal end of guidewire 34 is positioned within the biliarytree (including the common bile, hepatic or pancreatic ducts), rapidexchange catheter 32, in accordance with the present invention, may beback-loaded onto guidewire 34. Distal end 40 of catheter 32 is loadedonto the proximal end of guidewire 34. Rapid exchange catheter 32 isadvanced over guidewire 34, until the distal end 40 exits the distal endof the endoscope. Within the endoscope, distal from opening 52, theguidewire passes through guidewire lumen 58, and proximal to opening 52,the guidewire is positioned adjacent catheter shaft 36.

Distal end 40 of catheter 32 tracks guidewire 34 through the orificeleading to the papilla of vater, and into the desired duct, such as thecommon bile duct. Once distal end 40 of catheter 32 is in position inthe common bile duct, catheter procedures may be performed, such asinjecting a contrast media, such as radiopaque dye, through ancillarylumen 54 and ancillary lumen 56 into the common bile duct forvisualization of the duct.

Since the proximal end of guidewire 34 exits the guidewire lumen 58 at alocation distal of the catheter 32 proximal end 38, shorter guidewiresmay be used by the physician as previously described herein. In oneembodiment, a 250 cm guidewire is used. The use of the shorter guidewireeliminates many disadvantages of using longer guidewires which wereapproximately 400 cm in length, while maintaining or improving theefficiency and outcome of the procedure.

Alternatively, if a guidewire 34 has not been previously positionedwithin the biliary tree, rapid exchange catheter 32 may be used toestablish access to the targeted anatomy location within the alimentarycanal. Catheter 32 is passed through the lumen of the endoscope, untildistal end 40 is guided up through the orifice into the papilla ofvater, and into the desired duct, such as the common bile duct. Theguidewire 34 is then inserted into the endoscope lumen adjacent catheter32. Guidewire 34 is advanced through opening 52 into guidewire lumen 58to the targeted area, such as the common bile duct.

Once guidewire 34 is in position, and the desired catheter procedure hasbeen completed, rapid exchange catheter 32 can be exchanged or removedfrom the endoscope, while leaving guidewire 34 in position for othercatheter procedures. Catheter 32 is removed from guidewire 34 bytracking catheter 32 back over guidewire 34 until guidewire lumen 58 isretracted completely off the proximal end of guidewire 34.

Referring to the embodiment of FIG. 2, if catheter 32 includes weakenedarea 60, once opening 52 is outside of the proximal end of theendoscope, catheter 52 maybe “peeled away” from guidewire 34 untilcatheter 32 is completely removed from guidewire 34.

Although catheter 32 is removed from guidewire 34, the position ofguidewire 34 is maintained within the targeted anatomy. Other rapidexchange procedures may be performed, such as the catheter assembly 30of FIG. 8 or FIG. 9 without having to re-establish a path to the targetarea of the anatomy to receive therapeutic or diagnostic treatment.These catheter assemblies may be loaded onto guidewire 34 using the samerapid exchange procedures as previously described herein.

If a convertible catheter (as shown in FIG. 3) or “slit” catheter (asshown in FIG. 4) are used, the physician may alternate betweenconventional and rapid exchange guidewire procedures since guidewirelumen 58 within these devices extend from distal end 40 to proximal end38.

If catheter 32 further includes a “port and channel” type configuration(FIG. 5), as rapid exchange catheter 32 is back-loaded onto guidewire34, the proximal end of guidewire 34 exits the distal or first port 66of the catheter 32. As catheter 32 is advanced over guidewire 34, theguidewire is “snapped” into guidewire lumen 58 via channel 70. Whencatheter 32 is fully advanced over guidewire 34, guidewire 34 exitsguidewire lumen 58 through proximal or second port 68.

With the “port and channel” technology, when catheter 32 is positionedwithin the endoscope, guidewire 34 is not located adjacent cathetershaft 36, but rather is positioned within guidewire lumen 58. Guidewire34 exits guidewire lumen 58 at second port 68, which is located outsideof and proximal to the proximal end of the endoscope. With thisconfiguration, additional working space is not required for guidewire 34to lie adjacent catheter 32 within the endoscope lumen. Thisconfiguration allows for more room within the working space of theendoscope, allowing for larger ancillary lumens within catheter 32itself.

The “port and channel” catheter configuration may be manufactured as acatheter unit, or, alternatively, existing catheter devices may beconverted or modified to include the “port and channel” design. Uponretraction of catheter 32 from the endoscope, guidewire 34 is peeledaway from the endoscope via channel 70 until first port 66 is retractedfrom the proximal end of the endoscope. The short length of catheter 32distal of first port 66, which does not include access channel 70, isretracted completely off the proximal end of guidewire 34.

As previously described herein, if guidewire 34 is not in positionwithin the targeted anatomical location, the rapid exchange catheter 32may be used to cannulate the path to the targeted location within thepatient's anatomy, such as cannulating the papilla of vater for accessto the ducts of the biliary tree. As previously described herein, thecatheter may then be removed, and other rapid exchange devices using thetechnology of the present invention may be exchanged over the guidewiresince the guidewire remains in position within the biliary tree.

As previously described herein, guidewire lumen 58 may be a tubularmember which is extruded integral the catheter 32 shaft, oralternatively, guidewire lumen 58 may be a separate tubular member whichis coupled to catheter shaft 36. Although in one preferred embodimentguidewire lumen 58 is a tubular member which is located proximate distalend 40 of the catheter shaft 36, it is recognized that guidewire lumen58 maybe formed anywhere along shaft 36, may be an extension of shaft 36coupled to the distal end 40, or guidewire lumen 58 may run the entirelength of shaft 36.

Another embodiment of the present invention is shown in FIGS. 10-15.FIG. 10A is a partial elevational view of one embodiment of a tubularmember 113. Tubular member 113A includes a shaft 115 having a distalopening 119 and a proximal opening 117. In one embodiment, proximalopening 117 is flared to allow easier insertion of a guidewire 34. FIG.10B is a cross-sectional view of tubular member 113A taken along line10B-10B of FIG. 10A. As seen in FIG. 10B, a lumen 121 extends betweenproximal opening 117 and distal opening 119.

FIG. 11 is a partial elevational view of the catheter 32 with thetubular member 113A shown inserted through channel opening 68 ofcatheter shaft 36 and into guidewire lumen 58, and advancedlongitudinally therein. Tubular member 113A includes a distal tip 114which may extend beyond the distal end of catheter 32, as shown in FIG.11. Except as described herein, this embodiment is substantially similarin design and use to that described with reference to FIGS. 1-9.

Tubular member 113 serves to convert a catheter having a C-shapedchannel design to one having an O-shaped channel design. As best seen inFIG. 13, the tubular member 113A is shown disposed within guidewirelumen 58, thereby converting the catheter from a C-channel design to anO-channel design. A guidewire 34 may enter through proximal opening 117and be advanced longitudinally therein through distal opening 119 andinto position within a body lumen. Tubular member 113, by providing anisolated environment for guidewire 34, secures the guidewire in placewithin the lumen 121. Thus, tubular member 113 allows for the use of asmaller diameter guidewire than would be possible with a catheter havingan unaltered C-channel design, wherein a small diameter guidewire wouldbe at risk of slipping out of the channel 70 to a position exterior tothe catheter 32.

Tubular member 113 may therefore be used in a method for exchangingguidewires during a biliary endoscopic procedure. The method includesthe step of inserting the tubular member 113 through the channel opening68 and into the guidewire lumen 58, and advancing it longitudinallytherein, preferably before advancing the catheter 32 over the guidewire34. The catheter 32 is then advanced over the guidewire 34 such that theguidewire 34 is disposed through the lumen 121 of the tubular member113. The method further includes retracting the guidewire 34 from thetubular member 113 and removing the tubular member 113 from the catheter32 through the channel 70. A second guidewire, whose diameter may begreater or less than that of the first guidewire, is then advancedthrough the guidewire lumen 58, wherein a proximal end of the guidewireexits the channel opening 68. In other respects, this method issubstantially similar to the methods detailed in the descriptions ofFIGS. 1-9.

The distal tip 114 of the tubular member 113 may extend beyond thedistal end of the catheter shaft 32 to define a tip which is moreflexible and smaller in profile than the distal end of the cathetershaft 32. The distal tip may be used to facilitate intraluminalnavigation, cannulation and dilation. As such, not only does the tubularmember 113 serve as a C to O channel converter as described previously,but the tubular member 113 may be used as a dilator or a cannula. As adilator or cannula, the tubular member 113 may have a length sufficientto extend 5 cm beyond the distal end of the shaft and have a tip profileof approximately 3F.

FIG. 12A shows an alternative, preferred embodiment of the tubularmember 113. FIG. 12B is a cross-sectional view of tubular member 113Btaken along line 12B-12B in FIG. 12A. FIG. 12C is a cross-sectional viewof the catheter 32 taken along line 12C-12C of FIG. 11, and reveals thecross-sectional profile of the guidewire lumen 58. Tubular member 113Bcomprises a tubular shaft 123 formed integral with an outer portion 125.In one embodiment, the outer portion 125 extends along the entire lengthof tubular member 113B, as shown in FIG. 13A. In another embodiment,outer portion 125 extends only over a portion (e.g., distal portion) oftubular member 113B. The distal tip 114B may have the outer portion 125removed such that the tubular member 113B may be used as a dilator or acannula.

FIG. 14 is a cross-sectional view taken along line 13-13 of catheter 32of FIG. 11 in which tubular member 113B has been advanced into guidewirelumen 58. The cross-sectional profile of tubular member 113B is designedto mate with the cross-sectional profile of the guidewire lumen 58 andchannel 70. Designing the cross-sectional profile of tubular member 113such that it mates with the guidewire lumen 58 and channel 70 isadvantageous in that a tighter seal is formed between the twocomponents, thus enhancing the pushability and column strength of thecatheter, as well as reducing the amount of fluid leakage through thechannel. FIG. 15 is a cross-sectional view taken along line 13-13 ofcatheter 32 of FIG. 11 in which guidewire 34 has been inserted into thelumen 121 of tubular member 113B. The design and use of tubular member113B is otherwise substantially the same as tubular member 113A.

FIG. 10A and FIG. 12A disclose specific embodiments of tubular member113, but it is recognized that other embodiments of a tubular membershaped to convert the catheter's C-channel design to an O-channel designare also within the scope of the present invention.

As tubular member 113 is designed to be disposed within guidewire lumen58, its outer diameter should accordingly be small enough to fit withinthe lumen, yet preferably large enough to sit against the wall of theguidewire lumen 58 to avoid slippage out of the channel 70 to theexterior of the catheter 32. Accordingly, a preferred outer diameter ofthe tubular member is between about 0.025 inches and about 0.040 inches,with a diameter of about 0.035 inches being especially preferred. Apreferred inner diameter of tubular member 113 is between about 0.014inches and about 0.025 inches, with a diameter of about 0.027 inchesbeing especially preferred.

The length of tubular member 113 should preferably be greater than thelength of the biliary catheter 32, for example, about 212 cm. In apreferred embodiment, tubular member 113 extends distally about 5 mmpast the distal tip of the biliary catheter 32. Those of ordinary skillin the art of biliary catheters will recognize that tubular member 113may be constructed out of a variety of commonly known materials usingconventional techniques.

FIG. 16 represents another embodiment of the catheter of the presentinvention in which the channel 70 extends from the opening 68 throughthe distal tip of the catheter. In other embodiments, the channel 70 mayreach the distal tip of the catheter but not extend 25 through it. Thisconfiguration may allow the operator to completely withdraw the catheterwithout the need for an assistant. FIG. 17A is a cross-sectional viewtaken along line 17-17 of the catheter shaft 32 in FIG. 16, showing thechannel 70 having a U-shaped cross-sectional profile. FIG. 17B is across-sectional view taken along line 17-17 of the catheter shaft 32 inFIG. 16, and showing an alternative embodiment in which the channel 70includes a C-shaped cross-sectional profile. In one embodiment, aproximal portion of the channel 70 includes a U-shaped cross-sectionalprofile as shown in FIG. 17A, and a distal portion of the channel 70includes a C-shaped cross-sectional profile as shown in FIG. 17B. In analternative embodiment, a proximal portion of the channel 70 includes aC-shaped cross-sectional profile as shown in FIG. 17B, while a distalportion of the channel 70 includes a U-shaped cross-sectional profile,as shown in FIG. 17A.

It will be understood, that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, material, and arrangement of parts without exceeding thescope of the invention. Accordingly, the scope of the invention is asdefined within the language of the appended claims.

1. A medical device for use in a biliary procedure, comprising: anelongate shaft having a proximal end, a distal end, and a lumenextending at least partially therebetween; wherein the shaft includes achannel that is formed therein and disposed distally from the distal endof the shaft, the channel being in fluid communication with the lumen;and wherein the channel has a first cross-sectional shape along a firstportion thereof and a second cross-sectional shape along a secondportion thereof.
 2. The medical device of claim 1, wherein the firstcross-sectional shape is different from the second cross-sectionalshape.
 3. The medical device of claim 1, wherein the firstcross-sectional shape is a U-shape.
 4. The medical device of claim 3,wherein the first portion of the channel is disposed proximally of thesecond portion.
 5. The medical device of claim 3, wherein the firstportion of the channel is disposed distally of the second portion. 6.The medical device of claim 1, wherein the first cross-sectional shapeis a C-shape.
 7. The medical device of claim 6, wherein the firstportion of the channel is disposed proximally of the second portion. 8.The medical device of claim 6, wherein the first portion of the channelis disposed distally of the second portion.
 9. The medical device ofclaim 1, wherein the first cross-sectional shape is a U-shape andwherein the second cross-sectional shape is a C-shape.
 10. The medicaldevice of claim 9, wherein the first portion of the channel is disposedproximally of the second portion.
 11. The medical device of claim 9,wherein the first portion of the channel is disposed distally of thesecond portion.
 12. The medical device of claim 1, further comprising anendoscope having a working channel formed therein and wherein the shaftis disposed in the working channel.
 13. The medical device of claim 12,further comprising a guidewire disposed within the lumen of the shaft.14. A medical device for use in a biliary procedure, comprising: anelongate shaft having a proximal end, a distal end, and a lumenextending at least partially therebetween; wherein the shaft includes afirst port disposed distally of the proximal end of the shaft, a secondport disposed distally of the first port, and a channel disposed betweenthe first port and the second port; wherein the first port has a firstwidth, the second port has a second width, and the channel has a thirdwidth; and wherein at least one of the first width and the second widthis greater than the third width.
 15. The medical device of claim 14,wherein both the first width and the second width are greater than thethird width.
 16. The medical device of claim 14, further comprising anendoscope having a working channel formed therein and wherein the shaftis disposed in the working channel.
 17. The medical device of claim 16,further comprising a guidewire disposed within the lumen of the shaft.18. A medical device for use in a biliary procedure, comprising: acatheter shaft having a proximal end, a distal end, a lumen formedtherein, and a channel formed therein that is disposed distally of theproximal end and is in fluid communication with the lumen; a toolcoupled to the catheter shaft for aiding the guiding of a guidewire intothe lumen, the tool having an opening formed therein that is in fluidcommunication with the channel.
 19. The medical device of claim 18,wherein the tool includes a gripping mechanism.
 20. The medical deviceof claim 18, wherein the tool includes a locking mechanism.
 21. Themedical device of claim 20, wherein locking mechanism includes anoperating mechanism.
 22. The medical device of claim 18, wherein thechannel has a first cross-sectional shape along a first portion thereofand a second cross-sectional shape along a second portion thereof. 23.The medical device of claim 22, wherein the first cross-sectional shapeis a U-shape and wherein the second cross-sectional shape is a C-shape.24. The medical device of claim 23, wherein the first portion of thechannel is disposed proximally of the second portion.
 25. The medicaldevice of claim 23, wherein the first portion of the channel is disposeddistally of the second portion.
 26. The medical device of claim 18,wherein the channel is disposed between a first port and a second port,wherein the first port has a first width, the second port has a secondwidth, and the channel has a third width, and wherein at least one ofthe first width and the second width is greater than the third width.27. The medical device of claim 18, further comprising a guidewireextending through the opening in the tool, through the channel, and intothe lumen.
 28. The medical device of claim 18, further comprising anendoscope and wherein the catheter shaft is disposed within theendoscope.